From patchwork Tue Feb 18 18:12:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 11389235 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BAFB01395 for ; Tue, 18 Feb 2020 18:12:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9575621D56 for ; Tue, 18 Feb 2020 18:12:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hhOKKLMK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9575621D56 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=eRnJLlrKqPaGGyP0RHDPip1N/0GTQxPJI/yDvh4NisM=; b=hhOKKLMKcSBQVc xnVkomV6B4gbnzBvMJLUHEkc+/nn+sSAhSU2tEM1dxJIZPOZ4AnyYuHZ+aTc8YW29+6Qp0Swz0F8g kND75j0vW7jFPSb7GrU75RhBgaWIRkIaeiDrkU34OttLniy77bweiiwcqBQaYnMGCzXSbAzUdgYkv WoZfEMWcXQ/VfQ1j/T8jCzosv09npDAt0qFcLO3xFrlL3GHMgjdxOgtN/2x2A/aqFo8P8DpZUe0Bb p4JvQKe1Z8tk7IAIvFh54DxjDuwfyakPjvh2TD1je08uy0vTuAcO7A94OtyeWmIwWn4SclE2y3s0E N6nLraSJ/PzBX30kqo2Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j47Mb-0006xf-2l; Tue, 18 Feb 2020 18:12:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j47MY-0006wx-70 for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2020 18:12:51 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9FE9D101E; Tue, 18 Feb 2020 10:12:49 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 82C723F73B; Tue, 18 Feb 2020 10:12:48 -0800 (PST) From: Robin Murphy To: joro@8bytes.org, robdclark@gmail.com Subject: [PATCH] iommu/qcom: Fix bogus detach logic Date: Tue, 18 Feb 2020 18:12:41 +0000 Message-Id: X-Mailer: git-send-email 2.23.0.dirty MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200218_101250_295128_50863C41 X-CRM114-Status: GOOD ( 14.32 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stephan@gerhold.net, linux-arm-msm@vger.kernel.org, Naresh Kamboju , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, Brian Masney Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Currently, the implementation of qcom_iommu_domain_free() is guaranteed to do one of two things: WARN() and leak everything, or dereference NULL and crash. That alone is terrible, but in fact the whole idea of trying to track the liveness of a domain via the qcom_domain->iommu pointer as a sanity check is full of fundamentally flawed assumptions. Make things robust and actually functional by not trying to be quite so clever. Reported-by: Brian Masney Tested-by: Brian Masney Reported-by: Naresh Kamboju Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu") Signed-off-by: Robin Murphy Tested-by: Stephan Gerhold --- drivers/iommu/qcom_iommu.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/drivers/iommu/qcom_iommu.c b/drivers/iommu/qcom_iommu.c index 39759db4f003..4328da0b0a9f 100644 --- a/drivers/iommu/qcom_iommu.c +++ b/drivers/iommu/qcom_iommu.c @@ -344,21 +344,19 @@ static void qcom_iommu_domain_free(struct iommu_domain *domain) { struct qcom_iommu_domain *qcom_domain = to_qcom_iommu_domain(domain); - if (WARN_ON(qcom_domain->iommu)) /* forgot to detach? */ - return; - iommu_put_dma_cookie(domain); - /* NOTE: unmap can be called after client device is powered off, - * for example, with GPUs or anything involving dma-buf. So we - * cannot rely on the device_link. Make sure the IOMMU is on to - * avoid unclocked accesses in the TLB inv path: - */ - pm_runtime_get_sync(qcom_domain->iommu->dev); - - free_io_pgtable_ops(qcom_domain->pgtbl_ops); - - pm_runtime_put_sync(qcom_domain->iommu->dev); + if (qcom_domain->iommu) { + /* + * NOTE: unmap can be called after client device is powered + * off, for example, with GPUs or anything involving dma-buf. + * So we cannot rely on the device_link. Make sure the IOMMU + * is on to avoid unclocked accesses in the TLB inv path: + */ + pm_runtime_get_sync(qcom_domain->iommu->dev); + free_io_pgtable_ops(qcom_domain->pgtbl_ops); + pm_runtime_put_sync(qcom_domain->iommu->dev); + } kfree(qcom_domain); } @@ -404,7 +402,7 @@ static void qcom_iommu_detach_dev(struct iommu_domain *domain, struct device *de struct qcom_iommu_domain *qcom_domain = to_qcom_iommu_domain(domain); unsigned i; - if (!qcom_domain->iommu) + if (WARN_ON(!qcom_domain->iommu)) return; pm_runtime_get_sync(qcom_iommu->dev); @@ -417,8 +415,6 @@ static void qcom_iommu_detach_dev(struct iommu_domain *domain, struct device *de ctx->domain = NULL; } pm_runtime_put_sync(qcom_iommu->dev); - - qcom_domain->iommu = NULL; } static int qcom_iommu_map(struct iommu_domain *domain, unsigned long iova,